1. Field of the Invention
The present invention relates to an ophthalmologic apparatus for imaging and measuring an eye to be inspected and a control method of the ophthalmologic apparatus.
2. Description of the Related Art
Currently, various ophthalmologic devices using optical devices are used. For example, various devices are used as an optical device for observing an eye, including an anterior ocular segment imaging apparatus, a fundus camera, and an SLO (Scanning Laser Ophthalmoscope). Particularly, an optical tomography apparatus based on OCT (Optical Coherence Tomography) using multiple wavelength interference can obtain a high-resolution image of a sample and is becoming an indispensable ophthalmologic device in a clinic specialized to retinal diseases. This apparatus is used not only in ophthalmology but also in an endoscope or the like. This will be referred to as an OCT apparatus hereinafter.
The OCT apparatus can measure the slices of an object to be inspected by dividing measuring light that is low-coherent light into reference light and measuring light, illuminating the object to be inspected with the measuring light, and causing the reference light and return light from the object to be inspected to interfere with each other. The OCT apparatus can also obtain a high-resolution tomographic image by scanning the measuring light on a sample. The OCT apparatus can obtain a tomographic image of the retina on the fundus of an eye to be inspected, and is therefore widely used in ophthalmologic diagnosis of the retina and the like.
The OCT apparatus acquires a two-dimensional tomographic image by one-dimensionally scanning measuring light on a specific region, and acquires a three-dimensional image by repetitively acquiring the two-dimensional tomographic image while shifting its position. To reduce the influence of noise generated irregularly, the OCT apparatus adds a plurality of images captured in the same region and calculates the average value, of pixel values (see Japanese Patent Application Laid-Open No 2010-110392).
As described above, the ophthalmologic apparatus needs to acquire tomographic images in various scanning patterns for various parts of the eye to be inspected.
On the other hand, Japanese Patent Application Laid-Open No. 2011-024930 discloses an OCT apparatus that prepares a plurality of scanning patterns in advance for each morbid portion. It is therefore possible to obtain an appropriate tomographic image for each portion of the eye to be inspected. In addition, Japanese Patent Application Laid-Open No. 2011-092702 discloses an OCT apparatus that performs inspection using a plurality of scanning patterns while conforming the state of a morbid portion. This makes it possible to roughly capture and confirm the whole fundus of the eye to be inspected in the first scanning cycle and decide the part of interest and after that perform more specific imaging.
The OCT apparatus generally performs inspection using a plurality of scanning patterns, as described above. This will be referred to as an inspection set. The inspection set is repetition of measurement and imaging result confirmation. An OCT apparatus capable of more smoothly performing inspection even during measurement is demanded.
In the ophthalmologic apparatus disclosed in Japanese Patent Application. Laid-Open No. 2010-110392 or 2011-024930, however, no method of fixating the eye to be inspected during transition to the next inspection pattern in the inspection set is disclosed.
In the ophthalmologic apparatus disclosed in Japanese Patent Application Laid-Open No. 2011-092702, the fixation target is set in every inspection, though no method of fixating the eye to be inspected during transition to the next inspection pattern in the inspection set is disclosed. The operator needs to instruct fixation line control of the eye to be inspected every time the next inspection pattern starts.
As described above, the operator needs to give consideration to make measurement smoothly progress even during the time after the end of one pattern inspection to The next pattern inspection in the inspection set.